Electric regulator



Nov. 28, 1944.

F. NEWTON ELECTRIC REGULAIOR Filed Dec. 17, 1941 .Jvmto lfedert}ck Jl@wt2,

NOV. 28, 1944. NEWTON 2,363,612

ELECTRIC REGULATOR Filed Dec. 17, 1941 2 Sheets-Sheet 2 \\-Z-'-I JI/47 Patentui Nov. 28, 1944 ELECTRIC REGULAIOR Frederick Newton, Derby, Enfland, asflxnor to Newton England Brothers (Derbr) Limitcd, Derby.

Application Decemlier 17, 1941, Serial No. 423,387 In Great Britain January 14, 1941 12 Claims. (c1. zo1 51) This invention relates to electric regulators and more pmticularly has reference to regulators having carbon pile or other electric controlling elements actuated by the diflerential eect of opposed electromagnetic and spring forces.

In an electromagnet sstem the total contained energy is proportional to the product of the magnetic flux and the magneto motive force (i. e. the product of the flux and ampere turns) Negiecting leakage, fringing, and the ampere turns required by the iron in the magnetic circuit and/or assuming that for a given value of excitation the flux present in a system is inversely proportional to the length of the magnetic air path, the force of the attraction of the armature to the poles wi1i vary inversely as the square of the magnetic air path and where the air path is contained entirely between the armature and the poles, the attractive force wiil vary inversely as the square of the distance of the armature from the poles.

For various applications such as sensitive relays, carbon pile regtflators and the like it is desirable to provide for the magnetic attractive force an equa] and opposing force 1ree from hysteresis, so as to establish for a given degree of excitation a condition of diflerential equilibrium where small increases or deductions of excitation make available substantialiy large forces, through a desired distance in a positive or negative sense from the datum value as may be required for orational purposes.

Further it is very desirable that such a system should have the qualifies of a high natural period of mechanicai vibration, that is to say, the equi- Iibrium forces should be great compared with the weight of the moving parts, and that the system should be aperiodic, so as not to require a dash pot or other damping means and so as not to be resonant to any periodic influence.

An object of this invention is to provide an electric contiol apparatus having an electric modifying device actuated by the diflerential effect of the opposing actions of an electromagnet and a spring.

Another object of this invention is to provide a spring for opposing a variable magnetic force.

A further object of this invention is to provide an electric contre] apparatus having an electric modifying device actuated by the difierential effect of the opposing action of an electromagnet and a spring. said spring including at least two resilient leaves tangentially engaging and wrapping upon each other as they are stressed.

Still another object or this invention is to pro- Vide a spring for opposing an electromagnetic force and comprising at least two curved resilient leaflike elements tangentiaily engaging each other and connected at one end whereby fiexure of the free ends toward each Other W111 cause one element to wrap upon the other.

In the drawings:

Fi 1 is a vertical sectionai view of a control device constructed in accordance with the presont invention.

Fig. 2 is a plan view of the device shown in Fig. 1.

Fig. 3 is a somewhat diagrammatic illustration of a spring embodying the features of the present invention.

Fig. 4 is another diagrammatic view illustrating a modified form of spring.

Fig. 5 is still another diagrammatic view illustrating. a cantilever type of spring.

Fig. 6 is another diagrammatic view illustrating a modified form of cantilever spring.

Fig. 7 is a diagrammatic view illustrating a spring or unitary construction.

Fig. 8 is a view similar to that of Fig. 3 illustrating stiil another modified form of spring.

Fig. 9 is another diagrammatic view illustrating still another modified form of spring in which the ends of the two components are secured together.

Fig. 10 is a view similar to that of Fig. 3 illustrating a spring in which the components are formed of a plurality of layers which may be bimetallic.

Referring to the drawings, there is shown in Figs. 1 and 2 a carbon pile controller constructed according to the present invention.

As illustrated, an electromagnet is provided having a fixed core 1 surrounded by a magnet winding 2. A1ower lateral extension 3 i secured to the core l by means of a screw 4 which extends through an opening in the lower end of core I and is received in a threaded bore of the extension 3. The end 5 of screw 4 projects through the threaded bore in extension 3 and has the thread eut away and slightly rounded as shown for a pur- D se to be hereinafter described.

At the upper end of core I au upper1ateral extension 6 is mounted and secured in place by a screw 1 extending through an opening in the core 1 and enthreaded in the threaded bore 8 of the extension 6. The above construction provide a U-shaped core excited by the winding 2.

Cooperating with the U-shaped core formed of the core I and extensions 3 and 5 is an armature 9. A winding l 9 is carried by the armature intermediate its ends.

I! desired. winding I9 may be rigidly supportedarmature abuts and pivots, the lower end face 01 extension 3 serving as a fulcrum about which armature 9 pivots.

|An opening is formed in the upper end oi armature 9 in aiignment With the bore 9, and a screw I2 passes loosely through said opening and is enthreaded into the threaded bore 9 as shown Part of the bore in the upper end of armature 9 is enlarged to receive the sleve II 01 insulating material which serves as a'mandrel for the carbon dises I 4 of the carbon pile.

On the outer end of screw l2 adjacent the head thereo! is mounted a metal dise I3 which conductively engages the outermost carbon dise of the pile. the insulated sleeve in conductiv engagement With innermost carbon dise of the pile. Disc' l9 abats on insulating disc I1 which engages the armature 9. The dises I I! and I9 serve as the terminale of the carbon pile.

With the construction described it will be realized that upon energizing the windinss 2 and 19 of the electromagnet the armature will be attracted to the noie pieces which are in eflect the free end faces of the laterai extensions 3 and G. Movement or the armature 9 especially the upper portion thereoi. toward the magnet will permit the terminal dise l9 to be moved relatively to the terminal dise l3 to decrease pressure on the carbon pile Il.

has a threaded bore extending therethrough p rallel to the bore 9 and has a screw 29 threaded therein.

A stop block 2| is mounted on the upper end of armature 9 by means of screws 22.

As shown in the drawings, a spring 23 is positioned between the block 2I and the end of screw 29 which tends to move the block 2l away irom the end of screw 29.

Spring 23 is of special construction which is.

one 01 the features of the present invention and in this connection attention is directed to Fig.3 of the drawings which diagrammaticaily shows a spring imilar to spring 23. In Fig. 3, however, two be spring components 24 and 25 01 V- shaped formation are shown With the ends of one component in engagement With those of the other component and the apices or the two components remote from each other. Now when the spring components 29 and 25 are stressed relatively displacing the apices 29 and 21 toward each other to=the position shown in full fines in Fig. 3, the portions or the arms oi! one component inwardly trom the ends thereof are successively forced into contact With the corresponding portions of the arm et the other compo- A second metal dise I3 is mounted on nent. In other words. portions of one sprinz component are wrapped upon corresponding portions 01 the other spring component.

'Ihus one spring component serves as an abutment upon which the other spring component Wraps in a manner similar to that described in my copending application, Beriai No. 299,326, iiied October 13, 1939.

As the apices 29 and 21 are pressed together and as the regions 01 contact between the spring components 24 and 23 extendinwardly between the extremities of the components, the iree length of the components between the regions of contact decreases which increases the resistance of the spring components to further fiexure. I have found that a spring constructed as described relative to Fig. 3 resists flexure With a force inversely proportional to the square of the flexing displacement. Such a spring is ideal for use in opposing and balancing a force exerted by an electromagnet.

The spring 23 shown in Figs. 1 and 2 comprises a component 23 having its mid portion in engagement With block 2I and a component 29 having its mid portion in engagement With the end oi screw 29. 'It will be noted that the two components 23 and 29 are joined at one end as indicated by reference character 39 and that the free end of component 29 is formed as an extension 3l which is bent bac]: upon itseli to provide a supporting arm 32.

An opening is formed in the end of arm 32 by means of which said arm is mounted on screw 29.

A look nut 33 is threaded on screw 29 and serves to secure the arm 32 tightiy against block [8 which maintains the spring 23 in proper position between the stop block 2l and the end of screw 29. Look nut 33 also serves to look screw 23 in adJusted positions to which it may be moved to vary the initial stress on spring 23.

The parts oi! the device of Fiss. 1 and 2 are assembled as illustrated and screw 29 is adjusted to place spring 23 under the desired stress and screw I2 is adjusted to co0perate With the spring t0 subJect the dises of carbon pile Il to the pressure necessary to provide for the desired flow of current. With the windings 2 and I9 of the electromagnet subject to the electric current or potentiel to be regulated as the current or potential increases the electromagnetic force opposing spring 23 increases to reduce the pressure on carbon pile Il and thereby increase its resistance which serves to eflect a reduction of the current or potential to' which the electromagnet windings are sub1ected. This action produces the resulation desired. Now to maintain equilibrium between the magnetic force and the opposing spring force the latter must increase proportionaily tothe magnetic force. The sDring 23 is constructed to increase its resistance to flexure, as it is stressed, in a manner corresponding to the increase in magnetic force, and for each variation in the mmetic force exerted on 4 the armature there is a oorresponding variation o! inauiating matexial serves to insulate the core from the base Il.

A termina] box is mounted on the base. As-

shown, the side portions of the base are tumed up to provide flanges 15 to which screw sockeis 11 are attached for securing a housing 13 to the base In Figs. 1 and 2 a spring structure is shown which operates successully in this installation but a number of other forms of springs may be used. For instance, a spring as shown in Fig. 3

may be satisfactorily used if some means of retaining the components in associated relation is provided.

A spring of the type shown in Fig. 7 may be used. This spring is of unitary construction in that the two components 34 and 35 are integral.'

When the 8LDices 35 and 31 of this spring are urged toward one another, the portions 01' the two components from the joined ends 38 and 39 towards the apices are progressively brought into contact with each other to cause portions of one compommt to progressively wrap upon corresponding portions of the other oomponent in the manner described in connection With Figs. 1-3 even though the two components are integral;

In Fig. 9 a spring is shown formed of two separate components 40 and 4l which are joined at their ends by rivets 42. This spring functions in the same manner as the springs previously desCribed.

Those springs in which the two components are integril or joined are initially stressed in manufacture and can be more easily installed in an apparatus in which they are to be used than the unstressed springs.

In the preceding figures the springs have been shown as formed oi unitary constructions or embodying two separate or attached components.

It is conceivable however, as illustrated in Fig. 4, to construct a spring embodying the principies of the present invention wherein each component is formed of a pair of separate arms secured in place in a rigid body. As illustrated.in Fig. 4, the spring comprises a rigid body 43 having two arms 44 and 45 formed of spring material embedded therein. The rigid body 43 and the two arms 44 and 45 form one compone nt of the spring structure. As-

sociated with the aoresaid component is a second component formed of a rigid body 45 and arms 41 and 48 formed of spring material and embedded in the rigid body 45.

When the spring devioe of Fig. 4 is in an unstressed condition the arms of the several components will appear as iilustrated in dotted fines in Fig. 4 and when the spring is under stress the spring arms will assume the position shown in full lin. The function of the spring cf Fig. 4 is Dractcaily identical to that of the spring illustrated in Fig. 3 and the other figures. v

The springs described hereinbeore are all of what may be termed the beam type in that each component is in the form of a beam having two angularly positioned arms of V-shaped forma.- tion as shown in Fig. 3 or of the formation shown in Fig. 4. It is within the concept of the present invention, however, to utilize cantilever types of springs. In this connecticn there is shown in Fig. 5 of the dra wings a spring in which each component comprises a rigid element having a single resilient arm embedded therein. As illustrated, one oomponeht of the spring comprises a rigid body 49 having a resilient arm 50 embedded therein and the other combonent comprises a rigthereln. In the cantilever type of spring it is necessary to restrain the movement of the rigid bodies '49 and 5l so that they will move in a. flxed path relative to each other. The oontacting iree ends of the resilient elements 50 and 52 as indicated by refernce character 53 are free m move larally as in the case of the preceding figures. When the spring components are in an unstressed condition they assume the position shown in dotted limes in Fig. 5 and when in a stressed condition the portions of the spring clements 50 and 52 adjacent the ends 53 thereof progressively wrap upon each other in the same manner as described in connection with Fig. 3 to progressively shorten the eflective lengths of the arms 50 and 52 as the rigid bodies approach each other. 'Ihis spring construction functions in substantiaily the same manncr and has substantially the same characteristics as the springs of the so-called beam type hereinbeiore described.

In Fig. 6 there is illustrated a modified form of cantilever spring in which the two components 54 and 55 are integral or joined at thelr ends 55. The arms or components 54. and 55 01 the spring shown in Fig. 6 are initially curved as dis' tinguishedircm a true V-shape so that when the free ends 51 of the component 54 and 58 of the component 55 are moved toward each other, the portions of the spring adjacent ends 56 will progressively wrap upon each other as described in connection with the preceding figures.

The springs of Figs. 3, 7 and 9 have been described as having.components of V-shaped formation. It is not necessary that the components be of V-shaped formation but is only necessary that the arms thereof be angularly arranged as for instance, is the case -of the Structure shown in Fig. 4 or the components may. be of substantially U-shaped formation. In the latter case it is better that the components. be of an open U- shaped formation in which the arms of the p are initially fiaredoutwardly. In Fig. 8 of the drawings there is shown a spring construction in which the components 59 and 50 are of open U-shaped formation. When a spring of this type is placed under stress with the ends of one component in engagement With the other as indicated by reference characters 5l and 62 and the spring is stressed by causing the mid point 63 .of component 59 to approachthe mid point G4fof component 50, the end portions of one compcnent are wrapped upon the end portions of the other component as an abutment as described in connection With the preceding figures.

As is well known, temperature variations affect the functioning of shunt wound magnat windings and in order to compensate for such temperature variations the present invention includes the structure shcwn infig. 10. In this figure the spring is formed of two components 65 and 66, the component 65 being formed of two layers 51 and 58 and the component 86 being formed of two layers 69 and 10. The two layers of the components are of diierent metals or rather of metals having diferent coeflicients of expansion sothat the arms of the two components are in eiect of bi-metzl construction. The two metals fcrming the arms of the components are selected to produce the desired deformaticn under temperature variations to compensate for the effect of temperature variations upon the magnet windings. The spring construction shown in Fig. 10 apart from the bi-metallic structure opexates in substantially the same manncr,asthe structuf In some instances it may be desirabie to construct springs of a pluraiity of leaves in a manner aubstantially identica1 to that shown in Fig. 10 but in which the several layer-s or leaves o: each component are i'ormed of metal having the same coeflicients of expansion. In such a construction the operation wouid be substantially the same as that described in connection with Fig. 8.

In addition to the types of springs herein described it is also within the concept 01 the present invention to provide springs wherein each component comprises fine, two or a multiplicity of arms having their free extremities in. engagement l'or wrapping contact with the corresponding portions 01 a similarly constructed component. In such constructions there may be three or more arms for each component of the spring. Said arms may be iormed integral with each other and two components may, as a matter of fact, be integraliy formed ci each other. Alternativeiy, a plurality of arms may be embedded in rigid supports in a manner similar to that illustrated in Figs. 4 and 5 of the drawings.

From the toregoing description it will ce malized that the present invention comprises a pluraiity cf spring constructions which are useful for oppcsing the forces of attraction of electromagnets since their resistance increases with a displacement of a portion thereof in accordance with a law similar to that in which magnetic attraction increases with the air gap between the armature and the -pole pieces.

While the spring arms as illustrated in the drawings appear to be of uniform cross section throughout their lengths, it is within the concept of this invention to form said arms of modified cross sections.

Having described my invention, I ciaim:

1. An electric reguiator comprising a carbon pile, an electromagnet having two relativeiy movabie parts displaceable by eiectromagnetic action, to urge the relatively movable parts apart against the action of the magnet, two leaf spring components each formed of inclined arms, said components being positioned with the inner angles between said arms facing each other and the ends of the arms of one in contact with the ends of the arms of the other, means on one part of the electromagnet engaging one spring component between its arm ends, and means on the other part of the eiectromagnet engaging the other spring component between its arm ends, said spring components being operative to urge the said movable parts apart against the action of the magnet.

2. An electric regulator having a carbon pile, an electromagnet mechanicaily attached to one end of said pile, an armature for said electromagnet, a spring comprising two components each formed of inclined arms having their concave surfaces facing each other and the corresponding arm ends engaging each other tangentialiy, said spring being compressed between said eiectromagnet and said armature, and means connecting said armature and spring together and to the other end of said pile, so that movement of the armature towards the magnet wraps the arms of one spring component upon those of the other and the pile is subjected to the difference between the magnet pull and the spring pressure.

3. An electric regulator having a carbon pile, au electromagnet mechanically attached to one end of said pile, an armature for said electromagnet, a leaf spring of at least two arms abutting at one end upon each other tangentially to form a V, the other ends of said arms being compressed between said eiectrcmagnet and said armature, and means connectihg said armature to the other end of said pile. so that movement of the armature towards the mamet wraps the abuttinz spring ends one upon the other and the pile is subjected to the difierence between the masnet pull and spring pressure.

4. In a control apparatus, comprising an abutment device having mutualiy inclined surfaces, et resilient beam bridging said surfaces, an electromagnet having pole pieces, an armature, said pole pieces and armature constituting two relatively movable members, one of said members being connected to said abutment and the other member being connected to the mid point 01 the resilient beam, said members operating upon energization of the electromagnet te force the mid point of the beam rurther towards the angle between the surfaces of the abutment, causing the end portions of the beam progressively to contact the mutualiy inclined surfaces, progressively reducing the effective length of the beam bridged between them and progressively increasing the resistance to displacement by the electromagnet, and a carbon pile electric resistance having a movable member for varying the compression of the pile actuated by the relative displacement of said electromagnet pole pieces and armature; the construction that the abutment surface with mu tuaily inclined surfaces is resilient.

In a contro1 apparatus, comprising an abutment device having mutualiy inclined surfaces, a resilient beam bridging said surfaces, an electr magnet having pole pieces, an armature, said pole pieces and armature constituting two relatively movable members, one of said members bains connected to said abutment and the other member peins connected to the mid point of the resilient beam, said members operating upon energization of the eiectromagnet to force the mid point of the beam further towards the angle between the surfaces of the abutment, causing the end portions of the beam progressively to contact the mutualiy inclined surfaces, progressively reducing the effective iength of the beam brid3ed between them and progressiveiy increasing the resistance to displacement by the eiectromagnet, and a carbon pile electric resistance having a movable member and a movable element displaceable by the arma.

turc, to reiieve pressure on the carbon pile upon attraction of the armature to said core, and a spring opposing movement of the armature by electromagnetic force and compressing the carbon pile, characterized by said spring comprising two components each fonned cf inclined arms, said components having the inner angles between said arms facing each other and the corresponding arm ends engaging each other, whereby upon urging the components together intermediate their ends, greater portions of one component WII contact greater portions of the other adjacent their ends t0 shorten the span of the components between their contacting portions and thereby increase resistance to further fiexure.

7. An electric regulator comprising an electromagnet having a U-shaped core, an armature for bridglng the ends of said core, means includlng a rounded projection on said core for positionlng one end of the armature relative to one end of the core for movement about said core end as a fulcrum, means for positioning the other end of the armature relative to the other end of the core for movement toward and away from said other end of the core, a carbon pile having a fixed pile compressing element associated with said core and a movable pile compressing element associated wlth said movable end of the armature, and spring means for opposing movement of the movable end of the armature toward said core and for compressing of the carbon pile, said spring means being compressed between said core and the movable end of the armature.

8. An electric regulator comprising an electromagnat having a U-shaped core, an armature for bridging the ends of said core, fulcrum means whereby one end of the armature can turn about one end of the core, the other end of the armature having an opening therethrough, a screw carried by the core and projecting through the opening in the armature, a carbon pile with two terminal dises between which the pile is compressible said pile being mounted on the part of said screw projecting through the opening and having one terminal dise flxed to the end of said screw and its other terminal dise movable by said armature, and spring means for opposing movement of the armature toward said core and for compressing of the carbon pile.

9. An electric regulafor comprising an electromagnet having a U-shaped core, an armature 1or bridging the ends of said core, fulcrum means between one end of the armature and one end of the core, means for positioning the other end of the armature relative to the other end of the core for movement toward and away from said other end of the core, 9. carbon pile having a flxed pile compressing element associated With said core and a movable pile compressing element associated with said movable end of the armature, and sprlng means for opposing movement of the movable end of the armature toward said core and for compressing of the carbon pile, said spring means comprising two components each formed of inclined arms having their concave surfaces facing each other and the corresponding arm ends engaging each other tangentially and wrapping upon each other.

10. An electric regulator comprising an electromagnet having a U-shaped core, an armature for bridging the ends of said core, fulcrum means between one end of the armature and one end of the core, the other end of the armature having an opening therethrough, a screw carried by the core and projecting through the opening in the armature, a carbon pile with two terminal dises between which the pile is compressible said pile being mounted on the part of said screw projecting through the opening and having one terminal dise fixed to the end of said screw and its other terminal dise movable by said armature, and spring means for opposing movement of the movable end of the armature toward said core and for compressing of the carbon pile, said spring having two stressed components portions of which are wrapped upon each other.

11. An electric regulator according to claim 2 in which the two springs are joined together as a unit and one of them has an extension by which the unit is attached to the regulator.

12. An electric regulator according to claim 2 comprising also projections on said core and armature between which the two springs are lodged and an adjusting screw in one of said projections for varying the Initial compression of the springs.

FREDERICK NEWTON. 

